Aib-escape for pumps



UNITED STATES PATENT GFFICE.

HIRAM SMITH, or NORWALK, omo.

AIRESCALPE FOR PUMPS.

Specification of Letters Patent No. 14,372, dated March 4, 1856.

To all whom fit may concern:

Be it known that I, HIRAM SMITH, of Norwalk, in the county of Huron and State of Ohio, have invented a certain new and useful Improvement on the Air-Escapes of Double-Acting Pumps, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, which forms part of this specification, and in which- Figure l represents a vertical section (taken as indicated by the line m a2 in Fig. 3) of a double acting pump with my improvement applied thereto; Fig. 2 also a vertical section of the same, taken through the line a a in Fig. 3; and Fig. 3 a horizontal section taken as denoted by the line g/ y in Fig. l; and Fig. 4 a similar section through the line o, o, in Fig. l.

It is a common objection to double acting pumps that they generate confined air at or about or over the valves which in time interferes materially with the free and perfect operation of the pump, the air (when working under heavy pressure) forming an airspring over the' valves that unless relieved will stop their action; the plunger or piston rod in its downward stroke draws in air at the stuffing box and the pressure of the water against the packing prevents the air, in the reverse action, from escaping. This is a great evil and it is most sensibly felt in that construction of pumps which have both sets of valves arranged for convenience (and the convenience in facilitating repair and so forth is great) at the top, as not only the air entering from leakage but also air admixed with the water and drawn in by the suction naturally rises or keeps uppermost and over the valves. Numerous contrivances and arrangements have been proposed to obviate this defect and the ones in most common use consist of small holes drilled through the partition between the valve receiving chamber and discharge valve chamber, or small holes drilled directly through the cap of the receiving valve chamber communicating with the atmosphere and supplied with a funnel to hold water forming a l water valve to the air escape. These arrangements though partially effecting the purpose aimed at nevertheless .in practice fall far short of perfection and air to a greater or lessA extent accumulates about the valves, finding a much readier ingress than egress especially under rapid or heavy workare highly objectionable, while passages drilled through the partitions between the receiving and discharge valve chambers are objectionable on account that so soon as the direct stroke of the piston has delivered the accumulated air from the receiving valve chamber to the discharge valve chamber in sufficient quantity to fill said discharge valve chamber toa level with said passage or passages, the reverse stroke of the piston will bring back air instead of water and of course the discharge of air from the receiving valve chamber stops and the valve chamber becomes filled with air instead of water.

These and other defects peculiar to such air escape arrangements I obviate by my improvement which consists in the use and novel arrangement of interior air escape tubes that take the air, as it accumulates, from the very top of the receiving valve chamber and conduct it into the discharge pipe or discharge valve chamber below the valve seat and so low in the discharge as to insure t-he escape outlet being always under water. l

The pump represented in the accompanying drawing does not in its general character or construction possess novelty and belongs to that description of double acting pump for an improvement on which, similar in its general action to the one here represented, a patent was granted in March 1855, to C. Gr. Curtiss-the construction or arrangement however may be varied still to include the application of my improvement.

vIn the pump shown in the drawing, the piston (A) in its ascent produces suction in a branch pipe (a) which communicates with the pump barrel (B) near the bottom and with a chamber (C) near the top that is partially covered'by a discharge valve (b) operating or opening upward into a tioned chamber (D) in' the cap the other portion of the first referred to chamber (C) is open to a second upper partitioned space (F) in the cap which space forms one of the receiving valve chambers that has a suction or receiving valve (o) opening up into it and covering an aperture communicating with an under chamber (G) partifrom which branches the suction pipe (d). The piston in ascending causes, by the suction, water to be drawn from the suction pipe (d) into the under chamber (G), up through the receiving valve into the upper receiving valve chamber (F), from thence down through the opening (e) into the first named chamber (C) and down the branch pipe (a) Vinto the pump barrel, beg neat-h lthe piston. In descending, it will be obvious, the piston will close the receiving valve (c) and force the water in the pump upward through the discharge valve (b) into the discharge valve chamber (D) from whence it will pass down an opening (f) into the discharge pipe (7L) and while this action is going on, water is being drawn in by suction from the top of the piston through a second receiving valve (0) opening up into a further receiving valve chamber (F) and covering an aperture communicating with the under chamber (G) that connects with the suction pipe (cl) this second receiving valve chamber (F) freely connects with the pump barrel at the top and has an opening (e) that connects with an under chamber (C) that is partially covered by a second discharge valve (bf) opening upward into the partitioned or discharge valve chamber (D) in the cap that communicates by opening (f) with the discharge pipe (h). Tater thus drawn in on to the top of the piston by its descent is, on the ascent of the piston, forced up through the second discharge valve (b) out into the discharge pipe (77,) and so on for both sets of valves alternately to keep up the required double action.

This construction, arrangement and operation of the valves and their chambers is a convenient one, but not here claimed as new. It however has prominently the defeet my improvement proposes to remedyV as adverted to at the commencement of this specification. All air drawn in by the pump naturally rises to and settle-s at the uppermost portion of the interior where 'the valves are situated and air passing, t-he stuffing boX of the pump also settles there, and thus there is a great tendency to excessive accumulation of air over the valves which greatly interferes with their free and perfect operation, the same acting as a cushion and under heavy pressure stopping the action of the pump, as referred to at the onset. The usual air escapes of connecting passages and openings to the atmosphere by water furnished as described at the beginning of this specification are objectionable for the reasons there given, and fail at all to remedy the defect in some instances. My improved arrangement of passages or tubes (s s) eifectually does so. These tubes (s s) are arranged internally and occupy such a position as to form at their top ends a freely open communication with the receiving valve chambers (F F) at the top of said chambers, and, by the dipping of the tubes downward and suitable bend of them, further to form, at lower ends of said tubes, a communication with the discharge at any point below the valve seats and suflicient-ly low to insure the lower ends of said tubes being always immersed in the water of the discharge; the Ylower ends of the tubes being shown in the drawing to enter the chamber or space that communicates with the discharge pipe (7a) and with the upper discharge valve chamber (D) by opening (f), thus preventing any return of air through the tubes by the suction act-ing alternately on them, and any accumulation of air above the receiving valve (c 0') will be forced by the direct action of the piston from the top of the receiving valve chambers before it can interfere with the action of the pump, down through the tubes below the valve seats and be passed olf with the discharge water, and thus is a perfect air escape provided by the specied arrangement of the tubes, which none of the other water valve air escapes not using said tubes and establishing a different connection, before referred to, can comparatively approach in point of practical effect as I have proved by experiment and for the reasons here given.

What I claim as new and useful herein, and desire to secure by Letters Patent, is-

The employment of tubes (s 8) arranged to take the accumulating air from the top or upper portion of the receiving valve chambers and conduct it below the valve seats into the water discharge of the pump substantially as specified.

In testimony whereof, I have hereunto subscribed my name.

IIIRAM SMITH,

Witnesses:

A Mos JONES, JAMES CROSBY. 

